Conveners
Entangled photons in the Earth's gravitational field
- P. Walther
Description
In the past decades, interferometry using quantum systems has emerged as a crucial tool for achieving ultrasensitive measurements. This development is not only interesting for exploiting quantum physics properties to enhance classical interferometers, but also for opening up the investigation of fundamental effects on quantum systems in the laboratory. A prominent example is the open question of how gravity alters quantum entanglement, whose answer would shine new light into the interplay of general relativity and quantum physics. For enabling such experiments quantum interferometers with unprecedented sensitivity will be needed.
Within this talk I will present a major step towards this possibility by demonstrating a high-precision Sagnac quantum optical interferometer that is capable of measuring Earth’s rotation. By exploiting maximally path-entangled two-photon states, we observe super-resolution of the rotation signal and achieve a rotation rate sensitivity of 5 μrad/s. This establishes a world record in the rotation sensitivity of quantum optical interferometers and surpasses the current state-of-the-art resolution by three orders of magnitude.
As outlook I will present our ongoing experimental research aiming to explore the interface between quantum mechanics and general relativity by performing high-precision experiments using entangled photon states as probe. For this purpose, a high-precision interferometer whose paths are subject to different gravitational potentials will be used.
